Inverse suppressor for x-ray systems



July 16, 1935.T l H. D. GARRETsoN 2,008,496

INVERSE vSUPPRESSOR FOR X-RAY SYSTEMS Filed Apri; 21, 19:54

l TTORNEY Patented July 16, 1935 UNITED STATES PATENT OFFICE INVERSE SUPPRESSOR FOR X-RAY SYSTEMS 1 Claim.

(Cl. Z-34) This invention relates to an inverse suppresis shown the effect attained through the use of sor for X-ray systems and has for its object to provide a simple, reliable and effective suppressor means of this character.

More specically, the invention contemplates the utilization of a resistance connected in parallel with a dry rectier, the rectifier and resistance being connected to the primary of the conventional high tension transformer used in X-ray systems.

In the accompanying drawing wherein an embodiment of the invention is shown, Fig. 1 is a diagram illustrating the location of the dry rectier and resistance in the X-ray circuit; and Fig. 2 is a diagram illustrating the reduction in the wave attained by the use of the improved suppressor. Y

In the accompanying drawing, I illustrates a conventional X-ray tube of the hot cathode type having a ilament 3 which is connected to the filament transformer 5 in the usual way. The tube is provided with the conventional anode 2 which is connected to the secondary 4 of the high tension transformer I5. The opposite end of the secondary is connected by the wire I6 to the lament 3 in the conventional manner illustrated.

At 6 is idicated the primary winding of the high tension transformer I5, one end 'I of said primary being connected to several dry rectiiiers 8 which are connected in parallel with a resistance 9. The wires I1 and I8 are connected to a suitable source of current.

The effect of this rectifying circuit located in the primary of the high tension transformer is clearly illustrated in Fig. 2. At the left of said iigure is the conventional transformer potential as it appears without the use of the rectiiiers 8 and resistance 9 in the primary. At the right the rectiers and resistance. It Will be seen in the curve shown at the left of the gure that the wave II above and that indicated at I2 below the neutral line Il), is of equal curvature. At 5 the right of the iigure, it will be seen that the upper wave I3 corresponds to that shown at II, while the lower wave I4 has been materially reduced, or approximately to of the wave I2, as shown in the left portion of the figure.

The reason for this inverse suppression or rather' partial suppression is as follows: The X-ray tube acts as its own rectier permitting current to ow for a half cycle only, that is, when the anode is positive.k The dry rectifier in the 15 primary circuit is so connected that current flows freely during this half cycle, but is checked and must flow through the resistance during the other half cycle. This resistance is chosen of such a value as to materially lower the primary 20 charging current ow and consequently the potential in the primary at this period.

The use of the dry rectiiiers and resistance in parallel with the rectiiiers, for this purpose have been found to be of long life and entirely 25 satisfactory in result.

What I claim is:

A non-resonant inverse-reducing means for X-ray systems comprising, a hot cathode X-ray tube, a high tension transformer having pri- 30 mary and secondary windings, lthe secondary winding being connected to the tube, a dry rectier being connected to one end of the primary winding, and a resistance in parallel with the rectifier, said means constituting a circuit the stable 35 operation of which is not dependent upon resonance and which causes no change in the normal form of the primary wave.

HARRY D. GARRETSON. 

